Earth's atmosphere has been puffing up in response to increasing levels of UV radiation from sunspots. This is good news for satellite operators, because a puffed up atmosphere helps clean up low-Earth orbit. "The number of cataloged debris in Earth orbit actually decreased during 2011," reports Nick Johnson in NASA's Orbital Debris Quarterly newsletter. "[The figure below] illustrates how the rate of debris reentries from the Fengyun-1C anti-satellite test of January 2007 increased during the past year."
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